Bak Jun Yong, Kang Youngho, Yang Shinhyuk, Ryu Ho-Jun, Hwang Chi-Sun, Han Seungwu, Yoon Sung-Min
Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin-si, 446-701, Korea.
Department of Materials Science and Engineering and Research Institute of Advanced Materials, Seoul National University, Seoul 151-755, Korea.
Sci Rep. 2015 Jan 20;5:7884. doi: 10.1038/srep07884.
Top-gate structured thin film transistors (TFTs) using In-Ga-Zn-O (IGZO) and In-Ga-O (IGO) channel compositions were investigated to reveal a feasible origin for degradation phenomenon under drain bias stress (DBS). DBS-driven instability in terms of V(TH) shift, deviation of the SS value, and increase in the on-state current were detected only for the IGZO-TFT, in contrast to the IGO-TFT, which did not demonstrate V(TH) shift. These behaviors were visually confirmed via nanoscale transmission electron microscopy and energy-dispersive x-ray spectroscopy observations. To understand the degradation mechanism, we performed ab initio molecular dynamic simulations on the liquid phases of IGZO and IGO. The diffusivities of Ga and In atoms were enhanced in IGZO, confirming the degradation mechanism to be increased atomic diffusion.
研究了采用铟镓锌氧化物（IGZO）和铟镓氧化物（IGO）沟道成分的顶栅结构薄膜晶体管（TFT），以揭示漏极偏置应力（DBS）下退化现象的可能根源。与未表现出阈值电压（V(TH)）偏移的IGO-TFT相比，仅在IGZO-TFT中检测到了由DBS驱动的V(TH)偏移、亚阈值摆幅（SS）值偏差以及导通状态电流增加等不稳定性。通过纳米级透射电子显微镜和能量色散X射线光谱观察直观地证实了这些行为。为了理解退化机制，我们对IGZO和IGO的液相进行了从头算分子动力学模拟。IGZO中镓和铟原子的扩散率增强，证实退化机制是原子扩散增加。
